SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '700006d3283a544e49fc1362d9511dc867f3b974e18f0605123481e198293c34' 
  AND token = '8YYDQXEzPzspPcUN96GKCxiItsu+YlI207tA1BF2U/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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