SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '395fae5dfe7cd41aa50781cd5835a0224ff7856b71309c9671aed1f1f63c2f60' 
  AND token = 'RhXUejPfqTkCFoGcOWKCnfJZBwZy9+kPp6dHpl8h+CM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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