SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfc8936dcdb2af857c6f4c078145da626a1546cc97c1523ec21e5759d5ef8ad9' 
  AND token = 'XuAQ86BVSUaOm5svY5YE0KfrURqOoaOZd1VroICWJHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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