SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb98da34b0dd3b24a15b7c9070a419bac46f2503d2cf6cc001032ab76e3f34fb' 
  AND token = '6Pk1AIKo7Isfe3l7gBx4T+GDW+NVp2cjVct4fbWBKq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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