SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd0cb1a923724d76aa52199febaade8b4d7b8a99e6479b2cf5cfe6cba91999486' 
  AND token = 'NIxrjYGSdiF00dVkB/7hHv26ruiUmdtd5/4mMZZ62wA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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