SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39ff033812768cd9859f3fb809be7fcf760e8a31f8df7cb501ad276ccbede2d7' 
  AND token = 'PqEsLnJn6rodnU3SW3Yhk4hvV8nukCeSvkFR6RPpR2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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