SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f569b24b55ea0c1b1ac83ef8e624cb2b43d940a5f09099a263ef45c5a38b4fd' 
  AND token = 'LrjM7T1wnj9FY2lzjqvpnAHq4St/oi/5Q4Ywr8ctdqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}