SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87b498f0ca5da1bd6c8040fa613616787775d0550ddf2c17e39c31a780a2aa42' 
  AND token = 'wMh6oxoV1MpNpJsRx77FxZ1O0KdRzjWvJZl5agMq/aE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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