SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '44eb2e302e823b913db0ab9efe8f984209cab88eb102686573978d2661ac6f89' 
  AND token = 'gJs5ImjDsywmCzFhJMpCBgzzxamalJ+UTSuXK2YM5k0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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