SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00477c147f3b3ecd05ef7fa24a64b5c9921de044e7c0b7120d8eb288a2ee17c0' 
  AND token = '0+HgFJ5tmyHQG6ZxAdCJYDDelfZFlurkS9ZJBeLbM5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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