SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4798a75b89480897693f0162f65a28a7ec44ed1e07abdf061c79b66c99b78b5c' 
  AND token = 'Yqr9Sjl7sz/rV7Z3LOCBThxoiX3XCE9QJj7yDP2a7fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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