SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b6e1d950b5d72766a2c47f2d1162286dbf2c5d74e9a307f2fce09cfd84f865f8' 
  AND token = 'Ohettvn8JoMAT/3cEs7h1hvnZwB1MYBbjz0UlV1GGjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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