SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '866937b413122907e4926cc5bb56604cf9e3ff6ba1c2006a2884989bfc1dccad' 
  AND token = 'e6fRs/g38QfDXBtqRjLOhrA0oFup2obAgRlsXJZ8vf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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