SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a34391a00ae30a42bceb9b47beb18bc0f3edc49c69113ea2aecd6e67b1449691' 
  AND token = 'BY0vFdxEOjzB4hAB8vyKPzgOh+xCPwHzDZZ7M228rcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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