SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f3019559dcd4744b11f2f93e62a6d4a51205ae34e2a011ff51d5804691343b9' 
  AND token = '7ZLkvGplTYXPjywaYpbHZcgSGLKqWQ/MamyE7J8Rwdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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