SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae9550d1fa20e8ec2c472ed7c47fd7c051baebe66aae52bac524805b2062a932' 
  AND token = '/ClmLbFrnKu+8Nna462wXhUZQkesaXVHkihQ5Ps9KXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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