SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e2d76ef2366e1b352a8d5afd831f436932060e5746374f96922f17419ccd7ff' 
  AND token = 'eBMLMP0QJhZX2KlOVZY1IvA2biHIE5Vpi0FyB0yuzrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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