SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74da4165c06a8e9207c5421205357313ab2d8bd3f1c2f78d8330e456d8586991' 
  AND token = 'T31hFZvqemk9ue4u/86om0Gl1iqM5uT/+CS9m+vhMj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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