SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1510404dac2bf660c4793d8a36216936ab802ac8ffcd57d23f51dad7e1d6130' 
  AND token = 'XtyCnwntuzQH+z00HnyILgovYVENH2MMIaoaAvrPA7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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