SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0712d75d122dda99d977efd01834de14f9d0e850e9f377214436db67a5ad7864' 
  AND token = 'vMFT8nctBUs8gIOIn8ScfdkyWQxSDrgFE5/eshLvzaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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