SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bf6ae1d10c3c53b99033ebbc370280fdfaa59a913f8c4d214baf876aad9c331' 
  AND token = 'phIB2jX0kHZEI1WbC6t/MiBpqCJlPQ7m+QYXzw0PSbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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