SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3bfc33807bb89103b26e7b6f611194e27d9f9193b706543d53cab1825f5d4d5' 
  AND token = 'Bqd7xLPgM1301xSKS/QpfNV2Ro4WoOz488gTovMp9dI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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