SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e798c37ad83270e96a530ca6e1c9ab8267c28b44e6c29d5fa5d887bb94aa6e73' 
  AND token = 'GMCM/5CjNnYzvH/6Rwnlp1BWF/s8n1+1hPrGlZJjd64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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