SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dc8adc7beacbf00da219ca5fb4e06daa10eb40f73b9952725065c1ce3ef3a73' 
  AND token = 'TI9dln2q6fcwrRAk7PyQphbt6PGKz/lBu7gpjEr2mHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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