SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b0e86af6671624e5b7ccaa98274827fb6154af225954b7a51a09ce830326505' 
  AND token = '8fREf5CGlZODVt9EO//KuVwmDBXqxHCzGwX0s/1/c+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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