SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a831b0a27541dbad39809ce3e148ea51a2cb5c57a80853745810a43d95fa4b4' 
  AND token = 'cEemkZ+v+cEcJjf297HzqdEjiJK7txsju1GI4otmuDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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