SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fa8d3435d9bc2bd600ed5c0311f1baaf2adc129b3765ba1f1b1149532457119' 
  AND token = 'Z9zf1GLs0TTVZwyhEGjGLZMQ6lOJ2/eo1U/OPkdVZzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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