SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '499cbaf5e09eb0cf9def70f721d41f85426a37a531cf80f83fb48645ac7d28af' 
  AND token = 'Vp1i6eYdpHOvwXk5eueKWwnwNg1z5MTQfCNSSwjNP2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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