SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ce6e2ebe851faaf38ea5cecab47294e30b3595808550323204d58e82ccd3b1e' 
  AND token = 'KUNGq0Ugn/a3RlGTKZ1Ep4NoSNdIuokpb9o6W2+gl0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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