SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53f01db132ac107b4001bf071ac8dd3ba44d397b92c7c166248d584ffbd0af5e' 
  AND token = 'YQwVhtHeqZ04NLq+jCb5umhIB+glwYvz5gAagcr8Klo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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