SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8874cbceb765cdfdcdc62683afcfe826e8748aad918bdf236963de5134ef083' 
  AND token = 'qk8h13vtgfIunSzPecAUZMgUJ6ny4ax1x0ny3Pmx2qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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