SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaecbd4b7ef7a6c8d122b8d5666633040fb5af77e4dd011efaaa0302dc397041' 
  AND token = 'mA7rpPhOIgbfoVe0YBRNjvCeYWBp0dUQhqBPHV48Bvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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