SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '304ba45b067811866546a7790a66ff89a615a97854db63e436d52fcaac125edc' 
  AND token = 'eqQfVPwLuKsdCqE95SwNF1SwQbzL5+TaQ2nCzT/vlz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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