SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b1f00a0c94ce4cba1f97ad66b2f42216b0cf7e37988a74335c9264b96e3014d' 
  AND token = 'ETH5LktWkzcxYrcPEVl1OmXehOoAARRUKxoV97q1w/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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