SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd71b9bdf93e792af99bcc7edd6f3d4afcfdf99cf678a4d197f318d8d3784a9e2' 
  AND token = 'SnKv7WVcYzAdTgLUJQPPRaf2HPjO/pZDBGn2JywoZ/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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