SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '806f57d7afc9e66e5c9448481865235e52b20cef019da1f7248d0d1c442d2495' 
  AND token = 'r8mdW3gTEPJyTBhJ2NLQT+ERhZeu/HJjgT7pq7iHngY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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