SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9cf28d8fd2a5afab1e413483039573b20cce2d044c62a5aed2370a43ada9a7ba' 
  AND token = 'S+8LUvIO9I58ipVwnqo1DfYV6xoTOBx7vm/ZooZktKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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