SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c574ac9febbbab9341ecbe466481d3066df774b37e0e2f176508f9e10443766' 
  AND token = '3JiBAjqM9Xl+K+nIssDzjPW22gun7RE7J2MyvNQBmTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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