SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eb6255b7b03c2341e470fd0519b16eb7424baa337da9afbb17b013cbecf7bff' 
  AND token = 'PF3Swmyb+ssV+A7nPliHP453WlYg0Akz2RWOhUcmCUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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