SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab90dd2890b92ca56d6b05e242a151e0898816b8c2d8592849490cb65379970d' 
  AND token = 'HuEQgnXSfKh+xsgXZK0Is4E71I2wtvbsaAzDKEHMyGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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