SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbe5a1147fe2cf031d1001fecfa9f4512be3b1d98c74c05e9ce4490989363cff' 
  AND token = 'mmsVuB/otXuikcrVOYXRuWiPuqYWJormzfEzVdYq8xM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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