SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '425ecb61c4729d4a48a5f34890c94eb8cda341f3692cb7d3d68da0dabf88782a' 
  AND token = '2GFMquugHnuUXp3SRFV6CEQTKLvTJNvKVjpQXPt9lmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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