SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1b7cd54af3866e5db2a61f6f5906edc0db6e6b0756dc070dbf01dc08bd1c641' 
  AND token = 'cxSFmiy+yv4dqgGTsWQB+amUsAGxchj+nUZkiEtOdTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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