SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12ee180e854e3696b51e2d29a11347d47d69b21031d37027d573acedd73da164' 
  AND token = 'fd4QBDuTLO9Nr1YhX2kHboehrvq4ePwaVEmCukGnV5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}