SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e63e53e00f115bc682689b0155aaa5d260328398e825efd4aa278e98e8dbc2ce' 
  AND token = 'WaBCHveVnFA/Z3Bcc2MtyFZ3EX78IBmGJ+R/5biiCUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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