SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '828654df327a3e071b7943f61ef8642011448ae494a2ccf79366510ae09a17cd' 
  AND token = 'FA5gN3Ou8UjXewZ7GKNdzeNSRTZ5sIK6NWlBNvCMUfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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