SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '28fd3e34edd54a585ab77689bc5919b1f426c1a9ff1f0709d8366477c2a2d732' 
  AND token = 'IuK9FneEeASLEdjVoszqSZMbx3ka74bceiC/9QoMxcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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