SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d9052298a3e8af267cb4b0d463e7db0448d02b9ee1c30978ad6084aeb1304e6' 
  AND token = 'kSrqfAWeOFyPWdVUGE/eVTLEryOjdHcRa9nROMFlbaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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