SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a049d2be56e66c9a54a32d8092958be35a95609b6dd29d8c64d27e9fb9106ee6' 
  AND token = 'u/tUIW5dF/I/ddyN/P6RG8iyB2OiWneMgdXkfasX/bU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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