SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9f6b299610103eb4ffbed2aa97b9a4596e21887dca6072f7cf329277af781e58' 
  AND token = 'qechgP0+ANLQZwdmobzR4c1vroZxyN8whx8oGzGjo3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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