SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79c2fb6b466cf82060112571174c89e9913b7662c7a019b486c64e3aa098bc9a' 
  AND token = '4lS3bDVZ1L2XqzreLM4ObbPIgEz1pXhkrEGDhkETda4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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