SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f4b4fa2bfc52bf5e6a04cc435ee2be0e25a11669adbf4633ca4d47fdf19951a' 
  AND token = 'gJBIIC+1aFzJUAK9w6nkN/rKiKgQPMv8oVvH6x6ZE/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}