SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf424cb90c4d6c833a2e58595e860d684dcb9053ef9c3f359f924416b99f281a' 
  AND token = '2d0gNDw3t1qYY+LhpBbLEEnq7jQXKi2aCV8Dvn+NB4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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