SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '367c3dc38367271719f21b9dcf6a54742b2f740ea358987523fce33d389649b5' 
  AND token = 'JmozV60a4LXpCUOut3DGygy1PbybY3g+lqFLg/FyQCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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