SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aec78555b306d4746d542bd5fa5b9f3c708ba604be315ff5e824c406b8f226d5' 
  AND token = 'O5h5/MTnxQJR/pe6cWWJ5BqQywjpqhsyluVDDZsBIHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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