SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4914b5fe598f6c7317c7650c2d41f0499786c94569ea059ce13b32d2c2322ba6' 
  AND token = 'A7IJ1XC2FCsqhYIIXZvjW+BMK+vDBxEUzNjjMCdBNGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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