SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f38edb2eb27c395b0f388466644dfc8706a643051aff88647ded15679d21c53d' 
  AND token = 'mBQrqCU4B8kiKl7+0+6bSRjO+wv1HTFC5GoRx13KW8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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