SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8a787ebf7c9bb144389df23c6584d6fcaed2a27ca6e976f3417360a910fb992' 
  AND token = '5xPn5MYK0+/apVJUYIvwn/dVva7p0hnmQFL9S0np4Jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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