SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3720d72670f44b64a1768f41624bd84b9bedd93a8979f5889efdb1a6cfca8695' 
  AND token = '3hxkNdZwa7epWTSgBu2lWsMUM/dHUcXb4VPOMw+LHwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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