SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c1481df10e25f492bf4a28640c43bae9e631e675469aaf42cf5c1b3c99d4159' 
  AND token = 'HRxcjNZoApb0F7xHs/P648xQuHsirE2Tz6THv/gn28c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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