SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a1999da598b366783fb179aaaf10f07ee7dac248fab74f52bbb2edd6bf8eb61' 
  AND token = 'nyLSWWAT8cddye/GkLHPHUiFKToxE7oM47owAsoRK+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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