SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '744e0e9fdf92e159328b859691724aaab20fd69b56dc44cc05bbdc8bd2f09452' 
  AND token = 'asfsFv54mNq2jOauauXhkNa3l9DMIbgy+RVay9+2pj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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