SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f32a99d5b3dcb07a5c3239c3bbc281b13bd8b17249ffa57b93cbf27f07fd7fed' 
  AND token = '/UDn+C1+DM5GT8XVXsls/MtpYoE3skUCqnsiSYBbONw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}