SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0db48cdecfae50bb628a7ef43aacd9c478967882349544b5bfb22fb21edbe6a6' 
  AND token = '5ikDfqcCL4Qg8BZQ6TubLSPp0Gv6GUTbVEjkio5DciY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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