SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ece4997db1d63a242433202913e300f88c59cb274c46c39f266993b3bdd0badf' 
  AND token = 'pnuyoe4U/Wak/jgNzDVdVAwWdMtvGgkzTJfjsiRBYpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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