SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36f87b9f8d58fbad7ff01400faef71c872bc1c7ac98c25f4bd82f1d135ae4317' 
  AND token = '7g5D2muVGfkKYmWE0Xl/CPtM4Mty7SC4VvqDgZxl/jg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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