SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b622f9f0def564e231e6296ff81f9b6512d1f5cc15c897d968c1df30415e6222' 
  AND token = 'l6YXniK3Bx9juc+eO5VDTRV8xrYKLc0+/kJYFHyewDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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