SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36eb7d6f9269cecc21675a0e237ca0e78996acbb90dd701a35ff62e869013a62' 
  AND token = 'Pp4eGaEk5vsPjO2JdFqxMiZ32LRBafMOMx4TfwbbhnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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